By default, PowerPoint adjusts the size of the text as you enter it to fit the placeholder (a box with a dashed or shadow-marked border). For example, if you type a bulleted list literal that exceeds the size of a placeholder, PowerPoint reduces the font size and line spacing until all the text is in place; for the title text, if some words go to the second row, reduce one font size to fit the single row. However, sometimes we may not need this "AutoFit" feature, and try to turn it off in the following ways.
Temporarily turn off the text AutoFit
When the text AutoFit feature is turned on, the AutoFit Options button appears to the left of the text when the text is resized for the first time. At this point, click the button, and then click Stop Adjusting text based on this placeholder (Figure 1), PowerPoint does not resize the overflow text, and the text AutoFit feature of this placeholder closes.
Figure 1
Permanently turn off automatic text adjustment
1. On the Tools menu, click AutoCorrect Options.
2. Click the Automatic Formatting tab as you type.
3. Under Apply as you type, clear the Automatically adjust caption text by placeholder check box and the Automatically adjust body text based on placeholders check box (Figure 2).
4. Click "OK" button.
Figure 2
We need to pay attention to two points, the first is to temporarily turn off text AutoFit in the AutoFit Options button menu, which does not affect the AutoFit setting in the AutoCorrect dialog box, or the automatic adjustment of text in the Notes window when you turn on or off the body AutoFit feature.